Method to reduce the formation of high boiling compounds during the dehydrochlorination of 1,1,1,3-tetrachloropropane

Abstract

This invention relates to a method to improve 1,1,3-trichloropropene (HCC-1240za) and/or 3,3,3-trichloropropene (HCC-1240zf) selectivity in the dehydrochlorination of 1,1,1,3-tetrachloropropane (HCC-250fb). In normal practice, FeCl 3 is used as the catalyst for the dehydrochlorination of HCC-250fb to produce 1,1,3-trichloropropene and/or 3,3,3-trichloropropene. Here the improvement comprises, using as the starting material, a mixture comprising HCC-250fb and Heavies generated from the reaction of CCl 4 and ethylene to produce HCC-250fb, wherein the Heavies comprise one or more tetrachloropentane isomers. These compounds reduce or eliminate the formation of unwanted high boiling compounds (HBCs).

What is claimed is: 
     
       1. In the process of the catalytic dehydrochlorination of 1,1,1,3-tetrachloropropane (HCC-250fb) to produce 1,1,3-trichloropropene and/or 3,3,3-trichloropropene, the improvement comprising, using as the starting material, a mixture comprising HCC-250fb and Heavies generated from the reaction of CCl 4  and ethylene to produce HCC-250fb, wherein the Heavies comprise one or more tetrachloropentane isomers wherein the dehydrochlorination catalyst comprises one or more metal halides or mixtures thereof and the dehydrochlorination reaction temperature ranges from 50 to 140° C. 
     
     
       2. The process of  claim 1 , wherein the dehydrochlorination catalyst comprises FeCl 3  and/or FeCl 2 . 
     
     
       3. The process of  claim 2 , wherein the dehydrochlorination reaction temperature can range from, but preferably 80° to 120° C. 
     
     
       4. The process of  claim 2 , wherein the dehydrochlorination reaction time can range from 0.5 to 10 hours. 
     
     
       5. The process of  claim 2 , wherein the dehydrochlorination reaction time can range from 1 to 4 hours. 
     
     
       6. The process of  claim 2 , wherein the weight ratio of the catalyst to the reactant 1,1,1,3-tetrachloropropane can range from above 0 to 5% by weight. 
     
     
       7. The process of  claim 2 , wherein the weight ratio of the catalyst to the reactant 1,1,1,3-tetrachloropropane can range from 0.01% to 0.5% by weight. 
     
     
       8. The process of  claim 2 , wherein the concentration of tetrachloropentane isomers in HCC-250fb+Heavies range from 0.001% to 5% by weight. 
     
     
       9. The process of  claim 2 , wherein the concentration of tetrachloropentane isomers in HCC-250fb+Heavies range from 0.1% to 2% by weight. 
     
     
       10. The process of  claim 2 , wherein the concentration of tetrachloropentane isomers in HCC-250fb+Heavies range from 0.3% to 1.0% by weight. 
     
     
       11. A process for the catalytic dehydrochlorination of HCC-250fb to produce 1,1,3-trichloropropene and/or 3,3,3-trichloropropene, comprising dehydrochlorinating HCC-250fb using metal halide catalyst at a temperature from 50° to 140° C. and reaction time from 0.5 to 10 hours; wherein the dehydroclorination process includes one or more tetrachloropentane isomers. 
     
     
       12. The process of  claim 11 , wherein the tetrachloropentane isomers comprise 1,1,1,5-tetrachloropentane. 
     
     
       13. The process of  claim 11 , wherein the tetrachloropentane isomers comprise 1,3,3,5-tetrachloropentane. 
     
     
       14. A process for the catalytic dehydrochlorination of HCC-250fb to produce 1,1,3-trichloropropene and/or 3,3,3-trichloropropene, comprising dehydrochlorinating HCC-250fb using metal halide catalyst at a temperature from 50° to 140° C. and reaction time from 0.5 to 10 hours; wherein the dehydroclorination process includes one or more trichloropentene isomers.